• Title/Summary/Keyword: Silene

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Stereochemical Induction in the Generation of 1-Chloro-1-phenyl-2-neopentylsilene

  • Bok Ryul Yoo;Il Nam Jung;Myong Euy Lee;Chang Hwan Kim
    • Bulletin of the Korean Chemical Society
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    • v.12 no.5
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    • pp.517-520
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    • 1991
  • The reaction of dichlorophenylvinylsilane with tert-butyllithium in hydrocarbon solvents at room temperature or below generated the Z and E-isomers of 1-chloro-1-phenyl-2-neopentylsilene. The intermediates were trapped by cyclopentadiene, anthracene and methoxytrimethylsilane to give a consistent 90/10 ratio for the Z-silene to E-silene adduct. This result was interpreted as an evidence for stereochemical induction in the silene generation reaction.

Photoreactions of 2-(Pentamethyldisilanyloxy)phenylpentamethyldisilane

  • Park, Seung-Ki
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.1018-1024
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    • 2008
  • Photolysis of 2-(pentamethyldisilanyloxy)phenylpentamethyldisilane 1 in methanol provides five photoproducts 3, 4, 5, 6, and 7. Compounds 3 and 4 were probably formed from the methanol addition reactions of silene intermediate 2 and the formation of 5, 6, and 7 can best be explained by the nucleophilic attack of methanol to silicon atom in pentamethyldisilanyloxy or pentamethyldisilanyl group of the photoexcited state of 1. Irradiation of 1 in n-hexane gives a photoproduct 6 via silyl radical intermediate 8 and a novel intramolecular cyclization photoproduct 11 via silene 9 and silyl radical intermediate 10. Irradiation of 1 in deaerated methylene chloride in the presence of acetone affords a novel photoproduct 11 and phenol 7 but the expected photoproducts from the reaction of the silene intermediate with acetone were not obtained.

Photoreactions of (2-Alkoxymethylphenyl)pentamethyldisilanes

  • Park, Seung-Ki
    • Bulletin of the Korean Chemical Society
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    • v.27 no.9
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    • pp.1305-1309
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    • 2006
  • Photolysis of (2-hydroxymethylphenyl)pentamethyldisilane 1 in methanol provides a novel intramolecular photoproduct 4 via silene intermediate 2 but the photoreaction of (2-acetoxymethyl- or allyloxymethylphenyl) pentamethyldisilanes 5 or 10 in methanol affords unexpected photoproducts 8 or 13, respectively, instead of expected intramolecular photoproducts.

Newly Recorded Naturalized Species in Korea, Silene antirrhina L. (Caryophyllaceae) (한국 미기록 귀화식물: 가는끈끈이장구채(석죽과))

  • Bak, Gyu-Jin;Koh, Jae-Kee;Pak, Jae-Hong
    • Korean Journal of Plant Taxonomy
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    • v.41 no.2
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    • pp.171-174
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    • 2011
  • A naturalized species, Silene antirrhina L is newly reported in Korea. S. antirrhina L. was found along the Geumho riverside in Daegu. S. antirrhina L. is similar to S. koreana Kom. and S. armeria L. in that it has dark glutinous areas. S. antirrhina L. can be distinguished from congeneric species by the stamens and styles of its sepal and seed surface which are finely papillate. The Korean name of S. antirrhina L. "Ganeun-Kkunkkunijangguchea" was newly formulated based on the overall characteristics of this thin and small plant and on the Korean name of S. koreana Kom. photos of the habitat and a description and key of characteristics are provided.

An Estimation of the $\pi$-Bond Energy of 1-Methyl-1-Phenyl-2-Neopentylsilene

  • Lee Myong Euy;Paul R. Jones
    • Bulletin of the Korean Chemical Society
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    • v.15 no.6
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    • pp.469-473
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    • 1994
  • The E-and Z-isomers of 1-methyl-l-phenyl-2-neopentylsilene, generated by the sealed tube thermolyses of their anthracene adducts are stereospecifically trapped by trimethylmethoxysilane to give diastereomeric adducts. The temperature dependence of the ratio of the two diastereomers obtained when the silene formed from the pure E-or Z-anthracene adduct was trapped at higher temperatures permitted the determination of an activation energy for the silene isomerization. The activation energies for the E-to Z-and Z-to E-silene isomerization are $45{\pm}$6 and $20{\pm}4$ kcal $mol^{-1}$, respectively. The significance of these values is discussed.

A newly recorded alien plant, Silene fissipetala(Caryophyllaceae) from Korea

  • Jung-Hyun Kim;Yang-Hoon Cho;Seok-Soon Kim;Sunhee Sim;Min-Ha Kim
    • Korean Journal of Environmental Biology
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    • v.41 no.3
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    • pp.266-272
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    • 2023
  • Silene fissipetala Turcz., which is native to Continental China and Taiwan, was newly found in Chungcheongnam-do, Korea. S. fissipetala is similar to the related taxa S. antirrhina L., S. armeria L., and S. koreana Kom. in that it has glutinous zones. However, S. fissipetala is distinguished from the congeneric species by the presence of laciniate at the petals. The species grows on slopes and roadsides, suggesting that it is likely to have been introduced through the installation of green sites and road construction. A precise description, photographs, voucher specimens and a key to related taxa are provided.

Reactions of 〔(2-N, N-Dimethylaminomethyl)phenyl〕methylvinychlorosilane with t-BuLi: Synthesis and Characterization of Five Isomeric 1,3-Disilacyclobutanes.

  • Lee, Myeong Yu;Jo, Hyeon Mo;Lee, Su Heung;Kim, Jang Hwan
    • Bulletin of the Korean Chemical Society
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    • v.22 no.6
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    • pp.593-596
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    • 2001
  • The reaction of [(2-N,N-dimethylaminomethyl) pheny] methylvinychlorosiane with t-BuLi in hexane solvent gave dimers, five isomeric 1,3-disilacyslobutanes which were weparated and charaterized. In trapping experiments with various trapping agents, no corresponding silene-trapping aduct was observed. We suggest that more important species for the formation of five isomeric dimers might be the zwitterionic species generated by virtue of intramolecular donor atom rather than the silene.

Ab initio Study on Structures, Energies and Vibrations of Methylammonium-(water)$_n$ (n=1-3) Complexes

  • Kim, Gwang Yeon;Jo, Yung In;Bu, Du Wan
    • Bulletin of the Korean Chemical Society
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    • v.22 no.6
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    • pp.597-604
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    • 2001
  • The reaction of [(2-N,N-dimethylaminomethyl) pheny] methylvinychlorosiane with t-BuLi in hexane solvent gave dimers, five isomeric 1,3-disilacyslobutanes which were weparated and charaterized. In trapping experiments with various trapping agents, no corresponding silene-trapping aduct was observed. We suggest that more important species for the formation of five isomeric dimers might be the zwitterionic species generated by virtue of intramolecular donor atom rather than the silene.

Chemical Constituents of Silene seulensis Nakai from Demilitarized Zone(DMZ)

  • Jung, Yeon Woo;Seo, Chan Gon;Lee, Ji Eun;Hong, Seong Su;Kwon, Jin Gwan;Shin, Hyun Tak;Jung, Su Young;Choi, Jeong Jun;Choi, Chun Whan;Kim, Jin Kyu
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.92-92
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    • 2018
  • Silene seulensis Nakai was used as traditional medicines in Korea, we collected plant from demilitarized zone (DMZ). S. seulensis was extracted with 30, 50, and 70% ethanol and partitioned successively with n-hexane, EtOAc, dichloromethane and BuOH. These extracts (30, 50 and 70% ethanol) were evaluated the cytotoxicity on B16F10 and Hacat cell lines. The LC-MS/MS data of each fractions (n-hexane, EtOAc, dichloromethane, and BuOH) were compared with MS library, combined with ultraviolet/visual (UV/Vis) and MS data for faster determine structure by database search results. This led to the identification of four compounds (1-4) from S. seulensis. These compounds was isolated first time from S. seulensis. Their chemical structures are elucidated by combinations of NMR and mass spectrometry techniques.

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Analytical Method Development of Isoscoparin in Silene seoulensis Extract Using HPLC (HPLC 를 이용한 가는장구채 추출물의 Isoscoparin 분석법 개발)

  • Kwon, Jin Gwan;Seo, Changon;Jung, Yeon Woo;Choi, Yongmun;Shin, Hyun Tak;Jung, Su Young;Choi, Jeong June;Kim, Jin Kyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.47 no.1
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    • pp.57-63
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    • 2021
  • In this study, isoscoparin was selected as an indicator component to develop Silene seoulensis extract as a functional cosmetic material, and we developed an analysis method using high performance liquid chromatography (HPLC) for quality control. HPLC was performed on a Unison US-C18 with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methanol at a flow rate of 1.0 mL/min at 35 ℃, and the detection wavelength was 330 nm. The HPLC method was performed in accordance with the international conference on harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.02 and 0.07 mg/mL respectively. Calibration curves showed good linearity (R2 > 0.99988), and the precision of analysis was satisfied (less than 0.46%). In addition, the recovery rate was in the range of 99.10 to 101.61%, it was shown to be accurate. This result indicated that the established HPLC method is very useful for the determination of marker compounds in Silene seoulensis extracts.